The present invention relates to an oscillating switch, more particularly to an improved oscillating switch provided with a click feeling-producing mechanism for producing a suitable click feeling when an operating knob is operated.
As a switch for controlling various electric equipments (such as a power window mechanism) mounted, for example, on a door trim of a car door, a related oscillating switch 60 as shown in FIG. 3 is known, which includes an oscillating switch 60 of the see-saw type in which an operating knob 61 is supported for pivotal movement about a support shaft 63 on a switch panel.
In this oscillating switch 60, a PCB (printed circuit board) 66 serving as a contact circuit member is provided between an upper casing 64 and a lower casing 65 spaced a predetermined distance T1 from each other. A pair of juxtaposed right and left switching elements 67 are fixedly mounted on the PCB 66.
A pair of pressing portions 68, corresponding respectively to the switching elements 67, are formed on and project from a reverse surface (lower surface in FIG. 3) of the operating knob 61, and the switching elements 67 are suitably pressed respectively by these pressing portions when the operating knob 61 is operated to be pivotally moved. A click feeling-producing mechanism (not shown) is provided within each switching element 67, and produces a suitable click feeling when the operating knob 61 is operated.
FIG. 4 shows another example of oscillating switch in which there is provided a click feeling-producing mechanism 79 separate from switching elements.
More specifically, in this oscillating switch 70, a PCB 73 serving as a contact circuit member is provided between an upper casing 71 and a lower casing 72 spaced a predetermined distance T2 from each other, and a rubber switch member 75 having rubber contact portions 74 is provided on the PCB 73.
When an operating knob 76 is pressed to be pivotally moved, one of a pair of pressing portions 77 and 77 formed on and projecting from a reverse surface (lower surface in FIG. 4) of the operating knob 76 depresses corresponding one of a pair of pressing pins 78 and 78, so that the corresponding rubber contact portions 74 of the rubber switch member 75 can be depressed. The rubber contact portion 74, thus pressed by the pressing pin 78, is buckled, so that a conductive piece (not shown) thereof is pressed against a switch contact, provided on the PCB 73, to close it.
The click feeling-producing mechanism 79 is provided between the reverse surface of the operating knob 76 and the upper casing 71, and includes a ball plunger 82 which is mounted on a mounting portion of the upper casing 71 and has a compression spring 81 urging a steel ball (pressing element) 80 in a direction (upward direction in FIG. 4) toward the reverse surface of the operating knob 76, and an operating portion 83 having a cam surface 83a which is held in sliding contact with the steel ball 80 so as to guide the same. When the operating knob 76 is operated, the click feeling-producing mechanism 79 produces a suitable click feeling of the operating knob 76 in accordance with a resistance of sliding contact between the steel ball 80 of the ball plunger 82 and the cam surface 83a of the operating portion 83.
In the related oscillating switch 60 shown in FIG. 3, the click feeling-producing mechanism is contained in the switching element 67, so that the height (the dimension in the upward-downward direction in FIG. 3) of the switching element 67 increases. Therefore, the switching elements 67 must be firmly fixed to the PCB 66, so that a gap xcex1 for receiving soldering leads of the switching elements 67 and snap-fit members thereof must be provided between the PCB 66 and the lower casing 65.
Therefore, it is difficult to reduce the spacing T1 between the upper casing 64 and the lower casing 65 in the oscillating switch 60, and a dimension X1 of a unit in the direction of its thickness (that is, the spacing between the upper casing 64 and the lower casing 65; the dimension in the upward-downward direction in FIG. 3) can not be reduced. Therefore, there was encountered a problem that it was difficult to achieve a thin design of the whole of the unit and a space-saving effect when the unit is mounted on a vehicle.
On the other hand, in the oscillating switch 70 shown in FIG. 4, the click feeling-producing mechanism 79 separate from the switching elements is provided between the operating knob 76 and the outer surface of the upper casing 71, and the rubber switch member 75 is adopted. Therefore, the spacing T2 between the upper casing 71 and the lower casing 72 in the oscillating switch 70 can be made smaller as compared with the oscillating switch 60 shown in FIG. 3.
However, the height H2 of projecting of the operating knob 76 from the outer surface of the upper casing 71 is considerably larger than the height Hi of projecting of the operating knob 61 of the oscillating switch 60 shown in FIG. 3.
Namely, the click feeling-producing mechanism 79 is provided between the operating knob 76 and the outer surface (upper surface in FIG. 4) of the upper casing 71, and the spacing between a support shaft 84, serving as an axis of pivotal movement of the operating knob 76, and each rubber contact portion 74 of the rubber switch member 75 is large. Therefore in order that each rubber contact portion 74 can be properly pressed, the pressing pin 78 needs to be interposed between the operating knob and the rubber contact portion 74.
Therefore, the pressing pins 78 are fitted respectively in guide portions 71a formed integrally on the upper casing 71 so as to move upward and downward, so that these guide portions 71a need to have a predetermined guide length (dimension in the upward-downward direction in FIG. 4) As a result, the dimension X2 of the whole of the unit in the direction of thickness thereof (that is, the spacing between the upper casing 71 and the lower casing 72; the dimension in the upward-downward direction in FIG. 4) can not be reduced. Therefore, as in the oscillating switch 60 of FIG. 3, there was encountered a problem that it is difficult to achieve a thin design of the whole of the unit (for example, a space-saving effect when the unit is mounted on a vehicle).
It is therefore an object of this invention to solve the above problems and to provide an oscillating switch which can achieve a thin design of the whole of a unit while securing a good click feeling when operating an operating knob.
In order to solve the aforesaid object, the invention is characterized by having the following arrangement.
(1) An oscillating switch comprising:
a lower casing;
a contact circuit member provided on the lower casing and including a through hole;
a rubber switch member provided on the contact circuit member and including a pair of rubber contact portions and a through hole;
an upper casing for covering the rubber switch member;
an operating knob pivotally supported by the upper casing;
pressing portions formed on the operating knob so as to depress the corresponding rubber contact portions, respectively; and
a click feeling-producing mechanism, for producing a suitable click feeling when the operating knob is operated, which passing through the through holes of the contact circuit member and the rubber switch member, wherein the click feeling-producing mechanism includes,
a cam surface formed on one of the operating knob and the lower casing,
a pressing element formed on the other of the operating knob and the lower casing, and
a urging member for urging the pressing element to the cam surface.
(2) The oscillating switch according to (1), wherein the cam surface is formed on a distal end of an operating portion which projects from the operating knob and passes through the through holes of the contact circuit member and the rubber switch member, and the urging member is received and held in a receiving recess in the lower casing.
In the above construction, the contact circuit member and the rubber switch member are provided on the lower casing, and the click feeling-producing mechanism is interposed between the operating knob and the lower casing, and extends through the contact circuit member and the rubber switch member. Therefore, the spacing between the upper casing and the lower casing can be reduced.
When the spacing between the upper casing and the lower casing is reduced, the distance between the axis of pivotal movement of the operating knob and each of the rubber contact portions of the rubber switch member can be reduced, and therefore any separate members, such as pressing pins, are not necessary for properly pressing the rubber contact portions, and the number of the component parts is reduced, and besides the provision of guide portions, having a predetermined guide length so as to respectively guide the pressing pins, is not necessary, and the height of projecting of the operating knob from the outer surface of the upper casing can be reduced.
Therefore, only those portions, corresponding respectively to the click feeling-producing mechanisms, project a minimum distance from the outer surface of the lower casing, and a thin design of the whole of a switch unit can be easily achieved while securing a good click feeling when operating the operating knob.